Hardy hibiscus
Hibiscus moscheutos · Malvaceae Popular
Flowers the size of dinner plates in red, pink or white from late summer, on a shrub-sized perennial that dies to the ground each winter and reappears very late in spring.
- Size
- 5 ft tall, 3½ ft wide
- Zones
- 4 to 9
- Light
- Full sun
- Flowers
- Late July to mid September
- Pets
- No toxicity recorded
- Job in a bed
- Specimen
A bed built around hardy hibiscus
The planner designed this bed around hardy hibiscus when this page was made: a 12 × 6 ft (3.7 × 1.8 m) naturalistic planting in zone 6, full sun. It chose the other plants from the 966 that suit those conditions, and says below why hardy hibiscus stands where it does.
The plants
- 1 Hardy hibiscus × 1, red
- 2 Winter heath × 11, pink
- 3 Mouse-ear coreopsis 'Nana' × 5, yellow
- 4 Switchgrass 'Cheyenne Sky' × 5, purple
- 5 Swamp milkweed 'Ice Ballet' × 3, white
- 6 Camassia × 3, blue
- 7 Red spider lily × 12, red
Why this plant
- The only bold leaves here. The rest are fine and medium. A change of leaf keeps plants distinct when nothing is in flower.
- The only open bowls. The others are bells, daisies, airy sprays and others. Shape reads at a distance, where colours blur.
Why here
- Anchors a back corner. At 5 ft it is the tallest plant here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to switchgrass 'Cheyenne Sky' (3 ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- One plant, alone. A feature plant is seen as an object, and needs clear ground around it.
Why now
- In flower for 9 weeks. From late July to mid September.
- Part of the bed's peak. With switchgrass 'Cheyenne Sky' and swamp milkweed 'Ice Ballet' in late July: 3 kinds at once. No week has more.
Planned as a naturalistic planting: low grasses and groundcovers, the matrix, make up 58% of the planted ground. The back corners are held by hardy hibiscus and swamp milkweed 'Ice Ballet', the tallest plants on the plan. Winter heath repeats along the bed to tie it together.
The planner's own design check: 9 Excellent, 7 Good, 1 Satisfactory. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where hardy hibiscus goes in a border
At 5 ft it belongs at the back of a bed. In the planner's ten height classes it is tall (4 to 5 ft).
Its job: specimen. A feature plant with a shape of its own. It stands alone with room around it, and repeats only at a distance.
Nothing hardy has bigger flowers. It is a single feature plant: one is a statement, a row is too much. Mark its place, because it does not show until June, and give it sun and plenty of water.
- A tropical look in a cold climate
- Rain gardens and wet soil
- A late-summer feature
What to plant with hardy hibiscus
Plants recorded as good partners for it, and what each pairing does:
- Swamp milkweed: in flower together for three weeks, from late July; medium leaves against its bold ones; happy in the same moist soil.
- Joe Pye weed 'Gateway': in flower together for eight weeks, from late July; happy in the same moist soil.
- Switchgrass 'Shenandoah': its green leaves are a setting for the flowers, before and after; fine leaves against its bold ones.
Questions about hardy hibiscus
Does hardy hibiscus need sun or shade?
Hardy hibiscus grows in full sun (6 or more hours of direct sun a day).
It wants soil that stays evenly moist, rich in organic matter, and plenty of water. It copes with soil that stays wet.
What zones does hardy hibiscus grow in?
USDA zones 4 to 9. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does hardy hibiscus flower in my zone?
In zone 5 it flowers late July to mid September. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 4 | Early August to mid September |
|---|---|
| Zone 5 | Late July to mid September |
| Zone 6 | Late July to mid September |
| Zone 7 | Mid July to mid September |
| Zone 8 | Mid July to mid September |
| Zone 9 | Mid July to mid September |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should hardy hibiscus be planted?
3 ft (90 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 3½ ft (100 cm), so a group knits into one patch.
It grows 5 ft (150 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many hardy hibiscus plants do I need?
At 3 ft apart, set out in staggered rows:
- 1 to fill 10 square feet (about 1 m²)
- 4 for a single row 10 ft (3 m) long
- 4 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one, with clear ground around it: a feature plant is seen as an object, and a group of them is a thicket.
In the bed above, the planner used one in one group.
Is hardy hibiscus poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Do deer eat hardy hibiscus?
They may. NC State does not list it as resistant to deer or rabbits. Where they visit, protect it, or plant it among ones they avoid.
What flowers after hardy hibiscus?
Hardy hibiscus is over by mid September. These start as it finishes and carry the same spot on, so it never goes flat:
- Garden chrysanthemum: from mid September to late October, 24 in tall, to stand in front of it and cover its fading stems.
- Montauk daisy: from mid September to late October, 3 ft tall, to stand in front of it and cover its fading stems.
- Tatarian aster 'Jindai': from early October to early November, 4 ft tall.
What does hardy hibiscus look like in winter?
Hardy hibiscus dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.
Is hardy hibiscus good for bees and butterflies?
Hardy hibiscus is visited by pollinators, specialist bees, butterflies and hummingbirds.
It is native to the United States and Canada.
More Hibiscus
- Hardy hibiscus 'Kopper King' Hibiscus 'Kopper King'
- Hardy hibiscus 'Lord Baltimore' Hibiscus 'Lord Baltimore'
- Rose of Sharon Hibiscus syriacus
- Rose of Sharon 'Blue Chiffon' Hibiscus syriacus 'Notwoodthree' (Blue Chiffon)
- Rose of Sharon 'Diana' Hibiscus syriacus 'Diana'
- Rose of Sharon 'Sugar Tip' Hibiscus syriacus 'America Irene Scott' (Sugar Tip)
- Scarlet rose mallow Hibiscus coccineus
In these guides
- Plants for wet soil and rain gardens
- Salt-tolerant plants for roadsides and coasts
- Pet-safe plants for a sunny border
- Native perennials for pollinators
- Garden plants native to Canada
- Plants for hummingbirds
- Plants for butterflies
- Plants for bees
- Tall perennials and grasses for the back of a border
- Plants for a white garden
Zone guides: Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Perennial
- Size
- 5 ft (150 cm) tall, 3½ ft (100 cm) wide
- Plant
- 3 ft (90 cm) apart
- Height class
- Tall (4 to 5 ft)
- Place in the bed
- Back
- Flowers
- Late July to mid September; open bowls; red, pink, white
- Leaves
- Bold texture, herbaceous; green
- Shape
- Upright, clumping
- Hardy in
- USDA zones 4 to 9
- Light
- Full sun
- Soil
- Rich, evenly moist
- Water
- High
- Feeding
- Moderate, in spring
- Family
- Malvaceae
- Comes from
- Southeast Canada, Central & Eastern United States, and NE Mexico
- Attracts
- Pollinators, specialist bees, butterflies, hummingbirds
- Stands up to
- Heat, humidity, salt, wet soil
Checked against NC State Extension and VASCAN (plants of Canada). Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.